Soil loss estimation and prioritization using geographic information systems and the RUSLE model: a case study of the Anger River sub-basin, Western Ethiopia

Abstract

Soil erosion is a major environmental problem that affects people's livelihoods and environmental health, particularly in developing countries. The present study aimed to identify soil erosion hotspot areas and prioritization in the Anger River Sub-basin for conservation planning. The Revised Universal Soil Loss Equation model and geospatial technologies were adopted to identify soil erosion hotspot areas and prioritization of the sub-watershed for conservation planning. Key parameters such as rainfall data, soil data, slope length and steepness factor, cover management, and conservation practices were used to estimate potential soil erosion risk in the sub-watershed. The results showed that the annual soil loss rate in the Anger River Sub-basin ranged between 0 and 932.6 t/ha/year with a mean annual soil loss of 83.7 t/ha/year. About 1,140.7 km2 (43.6%) and 220.6 km2 (8.4%) were categorized under very severe and severe soil loss types, respectively. The mid- and upstream areas, as well as the steeper parts of the sub-watershed, were highly exposed to soil erosion. This research provides tangible evidence in the decision-making process for soil and water conservation practices at a sub-watershed scale. Moreover, further research should be conducted at a micro-watershed scale to minimize the effects of soil erosion on the health and sustainability of the watershed.

GIS based soil loss assessment using RUSLE model: A case of Horo district, western Ethiopia

“…A research study conducted by Ref. [ 5 ] in the Anger River sub-basin showed that approximately 43.6% and 8.4% of soil loss were very severe and severe, respectively. A similar study also conducted by Ref.…”

“…In emerging nations like Ethiopia, where agriculture is the foundation of the economy, this issue is especially prominent [ 3 ]. According to rural land use systems, problems of soil disintegration, sedimentation, and cleaning in a certain part of Ethiopia are a chronic environmental problem [ [4] , [5] , [6] ]. In several highlands of Ethiopia, agricultural expansion and intensification, urbanization, and the extraction of timber and other distinctive resources will likely accelerate over the course of the foreseeable future in order to meet demand in the highland of Ethiopia [ 7 ].…”

“…The level of living for humans is determined by the sustainability of soil for agricultural production, which contributes over 95% to global food security [ 8 , 9 ]. The revised universal soil loss equation (RUSLE) is an empirical model that has been used all over the world to prioritize conservation efforts and predict soil erosion loss using GIS in high-erosional locations [ 5 , 9 , 10 ]. Determining the amount of soil loss, assigning a value to it, and prescribing conservation actions are therefore essential for resource management [ 2 , 11 ].…”

“…There is no doubt that this cycle is putting pressure on common assets through deforestation and overgrazing. In general, agricultural practices are the main cause of soil degradation in the highlands of Ethiopia [ 5 ]. The expanded population moved up the slopes of the woreda zone, clearing land to develop new agricultural land with extreme slopes of over 45% [ 14 ].…”

“…As conducted by Ref. [ 5 ] found that soil loss ranged between 0 and 932.6 t/ha/year in the Anger River Sub-basin in Ethiopia, with a mean annual soil loss of 83.7 t/ha/year, and conducted by Ref. [ 16 ] found that 82% of the total area is at high risk and requires immediate measurement in the north side of the Lake Tana sub-basin in Ethiopia, Amhara region, at Megech watershed.…”